Chap. VIII. SEXUAL SELECTION. 279 



by exposing them to any great danger. The develop- 

 ment, however, of certain structures — of the horns, for 

 instance, in certain stags — has been carried to a 

 wonderful extreme ; and in some instances to an 

 extreme which, as far as the general conditions of life 

 are concerned, must be slightly injurious to the male. 

 From this fact we learn that the advantages which 

 favoured males have derived from conquering other 

 males in battle or courtship, and thus leaving a 

 numerous progeny, have been in the long run greater 

 than those derived from rather more perfect adaptation 

 to the external conditions of life. We shall further see, 

 and this could never have been anticipated, that the 

 power to charm the female has been in some few in- 

 stances more important than the power to conquer other 

 males in battle. 



LAWS OF INHERITANCE. 



In order to understand how sexual selection has 

 acted, and in the course of ages has produced conspicuous 

 results with many animals of many classes, it is neces- 

 sary to bear in mind the laws of inheritance, as far as 

 they are known. Two distinct elements are included 

 under the term " inheritance," namely the transmission 

 and the development of characters ; but as these 

 generally go together, the distinction is often over- 

 looked. We see this distinction in those characters 

 which are transmitted through the early years of life, 

 but are developed only at maturity or during old 

 age. We see the same distinction more clearly with 

 secondary sexual characters, for these are transmitted 

 through both sexes, though developed in one alone. 

 That they are present in both sexes, is manifest when 

 two species, having strongly-marked sexual characters, 

 are crossed, for each transmits the characters proper to 



